1. Field of the Invention
The present invention relates to the interface between two members having fluid conduits therein to establish a substantially fluid-tight connection between the conduits. In particular, the present invention relates to the interface between two fluid conduits, each opening to a surface of a member intended to be joined, surface to surface, to the other member with the openings in registration wherein a resilient seal, such as an O-ring or the like, is resilient received between the surfaces, usually in a counterbore surrounding one of the openings. More particularly the present invention relates to an interface of the type described wherein means are provided allowing accurate testing for a missing and/or inoperative seal.
2. Description of the Prior Art
It is well known to utilize members which are mounted or assembled together in a surface-to-surface relationship with an interface establishing substantially fluid-tight fluid communication between fluid conduits defined in each of the members. Such conduits often are part of a pneumatic or hydraulic control or actuation system (see, for example, U.S. Pat. No.5,231,895; 5,222,404; RE 34,260; 4,678,017 and 4,877,048, the disclosures of which are incorporated herein by reference).
Typically, such interfaces involve a first surface having a conduit opening which is urged toward a second conduit having a registering conduit opening. A resilient seal member, such as an O-ring or the like, is usually resiliently deformably received between the surfaces. A countersunk or counterbore portion is provided for receiving the O-ring. In the final assembly, the O-ring is not visible and, thus, missing or damaged seals cannot be visibly detected without disassembly.
The quality of the various fluid interfaces is often tested by forcing pressurized fluid or air through the various conduits and looking for leaks. By way of example, a well-known method involves coating the interface in a soapy solution or immersing the interface in water, forcing pressurized air through the conduit system and looking for bubbles.
A drawback with the prior art fluid interfaces was that when the members were new and/or initially assembled, the surfaces would create a temporarily fluid-tight connection, even in the absence of the seal, which made detection of missing or inoperative seals difficult or impossible. Subsequently, as the assembled members were subject to wear, vibration and the like, the missing and/or damaged seals caused the fluid interfaces to become less effective and/or to fail.